Is 'couple' ever used in the sense of 'some'?

Is the usage of the word couple (as in, "I want to ask a couple of questions...") to mean 'some' or 'few' correct (as in, interpreting given example to mean "I want to ask a few questions")?

As a follow-up on the example, when someone says "I want to ask a couple of questions...", does the usage of 'couple' necessarily mean the two questions have to be related to each other, or can couple just mean 'two' in that context?

Yes. It's used all the time to mean an undefined small quantity.

Come here, I want to ask you a couple of questions.

This is likely to be more than two questions.

I've had a couple of ideas I'd like to go over with you.

Translation: Get ready to be bored.

But if you use it regarding specific items, it probably means just two:

Can you bring me back a couple of Cokes from the machine?

But don't be surprised if the person replies:

Sure. How many do you want?

Couple originally referred to a pairing (as in two things that go together) and later developed into simply meaning two but has since widened its meaning to a few or a handful.